With the advent of portable electronic devices, there has been a multifold growth in the usage of power sources used in these devices. Typically, these power sources come in the form of battery packs. The portable electronic devices use these battery packs as a source of power for driving various electronic circuits used in these devices. Further, once these battery packs get discharged after usage, they can be recharged by using a power source and appropriate charging circuits. However, for the convenience of users of portable devices, it is desired that a battery pack should supply power to a portable device for the maximum possible time duration. For example, once charged, battery packs in mobile phones can be used up to durations of 16-18 hours, depending on the usage of the mobile phone. Further, portable electronic devices have shape and size restrictions. Consequently, it is desired that the battery packs make optimal use of the available space in the portable devices.
Different types of portable electronic devices where these battery packs are used have different size restrictions and power requirements. For example, a battery pack used in a mobile phone will have different size and power restrictions from a battery used in a laptop. However, manufacturing and shipping of different types of battery packs for different portable devices add to the overall cost of these electronic devices. Consequently, to reduce the cost of shipping, the portable electronic devices are shipped without a battery pack. After receiving these devices at a location, these devices are connected to battery packs that are assembled locally by using locally available battery cells. Battery packs can be assembled by connecting one or more battery cells of equal or unequal capacity in series and/or parallel connection.
Further, battery cells having unequal power capacities vary in shapes and sizes. As a result, while assembling a battery packs by using locally available battery cells, care should be taken that the battery cells are selected such that they meet the power requirements and size restrictions of the portable electronic device. Also, in case battery cells of different capacities are used in a battery pack, it should be ensured that all the battery cells in the battery pack discharge at the same rate.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.